Add TryFrom trait for u32 -> PixelFormat

src/lib.rs

@@ -1,5 +1,7 @@
 #![no_std]
 
+use core::convert::TryFrom;
+
 const CMDLINE_SIZE: usize = 256;
 
 pub trait LoadProtocol: Sized {
@@ -73,3 +75,15 @@ pub struct ProtoV1 {
 
     pub cmdline:            [u8; CMDLINE_SIZE]
 }
+
+impl TryFrom<u32> for PixelFormat {
+    type Error = ();
+
+    fn try_from(f: u32) -> Result<Self, Self::Error> {
+        match f {
+            0   => Ok(PixelFormat::LfbRgb32),
+            1   => Ok(PixelFormat::LfbBgr32),
+            _   => Err(())
+        }
+    }
+}